• JSTS:Journal of Semiconductor Technology and Science
• /
• 제7권4호
• /
• pp.260-266
• /
• 2007

Analytical compact form models for the signal transients and crosstalk noise of inductive-effect-prominent multi-coupled RLC lines are developed. Capacitive and inductive coupling effects are investigated and formulated in terms of the equivalent transmission line model and transmission line parameters for fundamental modes. The signal transients and crosstalk noise expressions of two coupled lines are derived by using a waveform approximation technique. It is shown that the models have excellent agreement with SPICE simulation.

• 한국정밀공학회지
• /
• 제7권4호
• /
• pp.140-148
• /
• 1990

A mathemetical medel has been developed for the purpose of estimating the rolling force required for computer control of cold strip mills. The model consists of equations of rolling force. flow stress. friction coefficient and tension. By applying the model to a 6-High cold tandem mill, the computer simulation is then been possible for all kinds of steels except stainless steel and the effectiveness of the model has been confirmed in the practice.

• 정보교육학회논문지
• /
• 제8권4호
• /
• pp.547-554
• /
• 2004

교육은 적응적 하이퍼미디어 시스템에서 가장 큰 응용분야이다. 사용자 모형은 적응적 하이퍼미디어 시스템분야에서 매우 중요한 부분이다. 본 논문에서는 학습자의 수준에 따라 다양한 학습 내용을 제공할 수 있도록 신경회로망 기법을 이용하여 사용자 모형을 개발하였다. 개발된 사용자 모형의 성능평가를 위해 웹기본 개념, 멀티미디어, HTML에 관한 내용을 학습하는 하이퍼미디어를 가지고 시뮬레이션 결과 학습자의 수준에 따라 다양한 컨텐츠를 제공함을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1951-1956
• /
• 2003

It is known that HIV (Human Immunodeficiency Virus) infection, which causes AIDS after some latent period, is a dynamic process that can be modeled mathematically. Effects of available anti-viral drugs, which prevent HIV from infecting healthy cells, can also be included in the model. In this paper we illustrate control theory can be applied to a model of HIV infection. In particular, the drug dose is regarded as control input and the goal is to excite an immune response so that the symptom of infected patient should not be developed into AIDS. Finite horizon optimal control is employed to obtain the optimal schedule of drug dose since the model is highly nonlinear and we want maximum performance for enhancing the immune response. From the simulation studies, we find that gradual reduction of drug dose is important for the optimality. We also demonstrate the obtained open-loop optimal control is vulnerable to parameter variation of the model and measurement noise. To overcome this difficulty, we finally present nonlinear receding horizon control to incorporate feedback in the drug treatment.

• 한국융합학회논문지
• /
• 제12권10호
• /
• pp.45-53
• /
• 2021

교육 장소에서 실제 수업하거나, 시뮬레이션 환경에서 교육하는 방법에 대한 방향이 제시되고 있다. 4차 산업혁명 이후에 다양한 분야의 산업 발전이 이루어지고 있고, 특히 IoT와 관련된 교육이 실행되고 있는 실정이다. 제안 모델은 3D 환경에서의 시뮬레이션 시스템을 응용하여 큰 비용 없이 다양한 IoT 시스템을 간접적으로 구축하여 교육할 수 있는 모델로서, 아두이노 플랫폼을 기반으로 가상 리모트 IO를 구현하였으며, 이를 통하여 교육을 위한 시스템 구축비용의 경감과 시스템을 간접적으로 구축하여 학습할 수 있는 모델이다. 또한 교육과 관련된 콘텐츠들을 다양하게 실습할 수 있다. 테스트 코드를 작성하여 실제 시스템과 가상의 시스템과의 동작 일치성을 확인하였다.

• Journal of Astronomy and Space Sciences
• /
• 제28권3호
• /
• pp.241-252
• /
• 2011

A simulated network protocol provides the capability of distributed simulation to a generic simulator. Through this, full coverage of management of data and service handling among separated simulators is achieved. The distributed simulation environment is much more conducive to handling simulation load balancing and hazard treatment than a standalone computer. According to the simulated network protocol, one simulator takes on the role of server and the other simulators take on the role of client, and client is controlled by server. The purpose of the simulated network protocol is to seamlessly connect multiple simulator instances into a single simulation environment. This paper presents the development of a simulated network (simNetwork) that provides the capability of distributed simulation to a generic simulator (GenSim), which is a software simulator of satellites that has been developed by the Korea Aerospace Research Institute since 2010, to use as a flight software validation bench for future satellite development.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
• /
• pp.281-286
• /
• 2000

This paper describes a lateral guidance system of an unmanned vehicle, using a neural network model of magneto-resistive sensor and magnetic fields. The model equation was compared with experimental sensing data. We found that the experimental result has a negligible difference from the modeling equation result. We verified that the modeling equation can be used in the unmanned vehicle simulations. As the neural network controller acquires magnetic field values(B$\_$x/, B$\_$y/, B$\_$z/) from the three-axis, the controller outputs a steering angle. The controller uses the back-propagation algorithms of neural network. The learning pattern acquisition was obtained using computer simulation, which is more exact than human driving. The simulation program was developed in order to verify the acquisition of the learning pattern, learning itself, and the adequacy of the design controller. A computer simulation of the vehicle (including vehicle dynamics and steering) was used to verify the steering performance of the vehicle controller using the neural network. Good results were obtained. Also, the real unmanned electrical vehicle using neural network controller verified good results.

• ETRI Journal
• /
• 제20권4호
• /
• pp.301-326
• /
• 1998

In this paper, we have modeled and evaluated a new parallel processing system called Scalable Parallel computer Architecture based on Xbar (SPAX) for commercial applications. SMP systems are widely used as servers for commercial applications; however, they have very limited scalability. SPAX cost-effectively overcomes the SMP limitation by providing both scalability and application portability. To investigate whether the new architecture satisfies the requirements of commercial applications, we have built a system model and a workload model. The results of the simulation study show that the I/O subsystem becomes the major bottleneck. We found that SPAX can still meet the I/O requirement of the OLTP workload as it supports flexible I/O subsystem. We also investigated what will be the next most important bottleneck in SPAX and how to remove it. We found that the newly developed system network called Xcent-Net will not be a bottleneck in the I/O data path. We also show the optimal configuration that is to be considered for system tuning.

• Nuclear Engineering and Technology
• /
• 제54권5호
• /
• pp.1541-1548
• /
• 2022

The thermal conductivity of uranium oxide (UO₂) containing pores and grain boundaries is investigated using continuum-level simulations based on the finite-difference method in two and three dimensions. Steady-state heat conduction is solved on microstructures generated from the phase-field model of the porous polycrystal to calculate the effective thermal conductivity of the domain. The effects of porosity, pore size, and grain size on the effective thermal conductivity of UO₂ are quantified. Using simulation results, a new empirical model is developed to predict the effective thermal conductivity of porous polycrystalline UO₂ fuel as a function of porosity and grain size.

• 소음진동
• /
• 제4권3호
• /
• pp.319-325
• /
• 1994

The flucturation of the engine torque appears to be the major source of the torsional vibration of the automotive driveline. The reduction of this torsional vibration has become a significant problem, due to an increase in the flucturation of the torque of recent light weighted powered engines, along with the requirements of higher performance. The torsional vibration of the automotive driveline can be reduced by soothing the fluctuation by adjusting the torsional characteristics of the clutch-disc. Computer simulation of the engine- input gear train is a useful investigative tool on studying the torsional characteristics of the clutch-disc. In this paper, a dynamic model for the automotive driveline was developed, and the engine torque and drag torque of the model were evaluated withe experimental data. By executing a simulation using the model, it has become possible to obtain the clutch-disc torsional characteristics when the engine is idling and the clucth-disc torsional characteristics for reducing the torsional vibration has been suggested.